The need for various types of shelters from environmental elements, such as the sun, wind and rain, has long been recognized. Moreover, the advantages of having shelter structures which may be easily erected for use yet disassembled for storage has been realized. Thus, for example, tent structures have often been called upon to serve as dwelling units for sleeping, cooking or other living functions either for temporary or permanent use. Larger, "area shelters" have been developed to provide a pavilion structures that are, for example, commonly used in commercial, fair, exhibit and party applications such as used in traveling shows and exhibits, merchandise exhibits, carnivals and the like.
Utilitarianism has historically influenced shelter construction as a predominant concern. That is, most shelter structures has been designed primarily from a functional standpoint with less regard for aesthetic features. Some efforts have been made in recent years to create canopy or tent structures that not only provide shelter but which are also more aesthetically pleasing to the viewer. These developments have, in part, stemmed from improvements in fabric technology, such as the development of lighter-weight, stronger materials that more readily accept tension forces and which tend to better retain their shape in environmental conditions.
One such example of a structure with both aesthetic design and utilitarian function is found in my U.S. Pat. No. 4,942,895 issued Jul. 24, 1990 and entitled "Tensioned Tent Structure And Erection Method Therefor". This portable shelter is also subject of my design patent, Des. No. 326,133 issued May 12, 1992. In the '895 patent, a tensioned fabric structure is described wherein a flexible covering is configured to have one or more vertex portions and a peripheral edge which may be anchored at corner portions to a support surface. A pole assembly is associated with each vertex portion to elevate the vertex portion over the support surface and thereby provide a protected space for activities. Tension is placed upon the fabric structure by adjustably varying the effective length of the pole assemblies.
Another example of an aesthetically pleasing tent structure is shown in my U.S. Pat. No. 5,234,011 issued Aug. 10, 1993 and entitled "Clear Span Tent Structure". This shelter structure utilizes a flexible covering that has a center portion and a plurality of ridge portions which terminate at peaks located proximate to the coverings periphery so that the inclined slopes of the ridge portions form valley portions that extend radially outwardly from the central portion between a pair of adjacent ridge portions which also extend radially outwardly from the central portion. Support poles are located around the periphery to support the peak portions, and anchors secure the flexible covering to a support surface so that a ridge tension force is applied along each ridge line in a direction upwardly and outwardly with respect to the central portion and a valley tension force is applied along each valley floor in a direction downwardly and outwardly with respect to the central portion thereby holding the flexible covering in a taut condition when erected.
The integration of art and engineering with respect to fabric structures is further exemplified by fabric structures produced by Transformit, Inc. of Portland, Me., USA and by Bill Moss, Inc., of Scottsdale, Ariz., USA. The products produced by Transformit, Inc. are generally one of a kind pieces commonly referred to as fabric sculptures wherein large panels of fabric are specially configured and are stretched into a curvilinear contours, typically by guy wires. Not only are these products aesthetically pleasing, but they are also functional in providing shade and other shelter. A primary material used by Transformit, Inc. is spandex-nylon fabric. The products of Bill Moss, Inc., are often one of a kind tensile-structure canopies which are supported by guy wires, rigid poles and/or arched resilient poles. In each case, these products require specially configured panels to establish the unique curvilinear contour selected by the designer.
While the above described products have advanced the art of canopies, tents and shelters, they nonetheless have certain limitations and disadvantages. For example, the structures described in the '895 and '011 patents will have a standard appearance that is reproduced each time the tent or canopy is erected. While the products described in the '895 and '011 patents are readily erected and disassembled, these structures rely on specific anchor points and pole locations so that proper tensioning of the protective covering is assured each time the unit is erected.
Likewise, the structures of Bill Moss, Inc. are constructed to have a standard appearance when erected or, where designed to be one of a kind sculptures, are specifically configured to have a unique appearance. Similarly, the fabric sculptures of Transformit, Inc. are designed to take on a specific, unique appearance upon installation. Accordingly, the cost of each unique design can be very expensive. Indeed, the fabric structural sculptures of Bill Moss, Inc. and Transformit, Inc., typically rely on custom installation which greatly increases the cost and does not lend itself to repeated erection and disassembly for storage. Thus, none of these products allow for varied custom design enabling the user to establish different aesthetic appearances with the same structural elements.
Accordingly, there remains a need for an improved canopy or shade structure which can be set up and dismantled by an ordinary user whereby the user may create an almost unlimited variety of aesthetic appearances. There is a further need for such a shelter which is sufficiently inexpensive to be within the economic reach of a larger portion of the population than is heretofore possible with unique, one of a kind shelters. The present invention has been developed to meet these needs.